From 1942 to 1979, 3.24 grams of 0.980 copper
From 1980 to 1981, 2.8 grams of 0.980 copper
From 1982 to 1996, 2.5 grams of 0.980 copper
From 1997 to present, copper-plated zinc or copper-plated steel.
From 1980 to 1981, 2.8 grams of 0.980 copper
From 1982 to 1996, 2.5 grams of 0.980 copper
From 1997 to present, copper-plated zinc or copper-plated steel.



















